<template>
  <div>
    <el-dialog
      title="添加分类"
      :visible.sync="dialogVisible"
      width="50%"
      @close="addCateDialogVisible"
    >
      <el-form
        :model="addCateForm"
        :rules="addCateFormRules"
        ref="addCateFormRef"
        label-width="100px"
      >
        <el-form-item label="分类名称" prop="cat_name">
          <el-input v-model="addCateForm.cat_name"></el-input>
        </el-form-item>
        <el-form-item label="父级分类">
          <!-- 级联选择器 -->
          <el-cascader
            v-model="selectedKeys"
            :options="parentCateList"
            :props="{
              expandTrigger: 'hover',
              value: 'cat_id',
              label: 'cat_name',
              children: 'children',
            }"
            @change="parentCateChanged"
            clearable
            change-on-select
          ></el-cascader>
        </el-form-item>
      </el-form>
      <span slot="footer" class="dialog-footer">
        <el-button @click="dialogVisible = false">取 消</el-button>
        <el-button type="primary" @click="addCate">确 定</el-button>
      </span>
    </el-dialog>
  </div>
</template>

<script>
export default {
  data() {
    return {
      dialogVisible: false,
      addCateForm: {
        cat_name: '',
        cat_pid: 0,
        cat_level: 0,
      },
      addCateFormRules: {
        cat_name: [
          { required: true, message: '请输入分类名称', trigger: 'blur' },
        ],
      },
      parentCateList: [],
      selectedKeys: [],
    }
  },
  methods: {
    parentCateChanged() {
      console.log(this.selectedKeys)
      //如果selectedKeys 数组中的length大于0 ，证明选中的父级分类
      //反之，就说明没有选中任何父级分类
      if (this.selectedKeys.length > 0) {
        //父级分类id
        this.addCateForm.cat_pid =
          this.selectedKeys[this.selectedKeys.length - 1]
        this.addCateForm.cat_level = this.selectedKeys.length
        return
      } else {
        this.addCateForm.cat_pid = 0
        this.addCateForm.cat_level = 0
      }
    },
    addCate() {
      this.$refs.addCateFormRef.validate(async (valid) => {
        if (!valid) return
        const { data: res } = await this.$http.post(
          'categories',
          this.addCateForm
        )
        if (res.meta.status !== 201) {
          return this.$message.error('添加分类失败')
        }
        this.$message.success('添加分类成功')
        this.$emit('getCateList')
        this.dialogVisible = false
      })
    },
    //监听对话框关闭，重置表单数据
    addCateDialogVisible() {
      this.$refs.addCateFormRef.resetFields()
      this.selectedKeys = []
      this.addCateForm.cat_level = 0
      this.addCateForm.cat_pid = 0
    },
  },
}
</script>

<style lang="less" scoped>
</style>